Hello,I'm very happy to be a new member of this great community.I have a newbie question (sorry if this question has been asked before):Can I run a Bachmann MDT plymouth on the Kato Unitrack 117mm (4 3/5") radius curves ?Many thanks in advance for your replies.

I have managed to run those things on the Kato UNITRAM curves, which are pretty tight, but not as tight as the curves about which Original Poster asks. If I hardwire a pair together, they will go through the UNiTRAM turnouts without stalling, but singly, they stall on the UNITRAM turnouts.

Never have I had a problem running them on nine and three quarter curves. The KATO UNITRAM curves are tighter than nine and three quarters.

I run my MDT Plymouth switcher regularly on Kato's CV1 track set, including turnouts, without any problems. According to the CV1's packaging, the curves have a 6 inch radius (150mm). This is part of a mining operation on my layout and I usually run the locomotive with 3 or 4 short ore cars (Atlas). I have not experienced any problems. Since I do not have any track with a smaller radius, I cannot comment on that. Hope this helps.

I got out a piece of flex track and tested mine out and found that it ran fine on 9.75" radius, but as the radius got smaller the derailments became more frequent. The sharpest I tried was about 7" and could not get it to stay on track very long. Your results may vary... I would be weary of trying anything much sharper than 7 or 8 inches as the loco may run fine on 6" as Fred experienced or it may not.